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Signs of Dehydration in Children: How to Tell if Your Kids Are Dehydrated and What to Do About It!

Woman drinking water

Do you know the MOST important nutrient in the human body?

There are a lot of really good ones like magnesium, calcium, and Vitamin C. But those are not at the top of the list.


Plain and simple water. It makes up about 55-60% of your total body mass!

You can go a long time without proper nutrition. But you can only go a few days without water.

What are the Roles of Water in the Body?

Water has so many roles in the body. They include:

  • flushing toxins
  • removing waste
  • transporting nutrients
  • regulating body temperature
  • improving oxygen delivery to cells
  • moistening oxygen for easier breathing
  • preventing tissues from sticking
  • improving cell-to-cell communication
  • empowering the body’s natural healing process
  • improving lymphatic flow
  • maintaining the normal electrical property of cells
  • cushioning bones and joints

Without water, our bodies break down at a cellular level. So it is important to keep your kids well hydrated!

How to identify dehydration in kids

We can make about 8% of our daily water needs. But we have to ingest the remaining 92%! That’s a lot of water.

What are the Signs of Dehydration in Kids?

Believe it or not, dehydration is the most common nutritional deficiency in the American population. That means we have a lot of dehydrated people, kids included!

It actually doesn’t take much to experience symptoms of dehydration. Even a 2% drop in your body’s water content can make you feel fatigued. Water loss greater than 10% can lead to death.

So it’s important to watch for signs of dehydration in your kids so you can quickly remedy the situation. Some early signs of dehydration include:

  • fatigue
  • cravings
  • headaches
  • anxiety
  • irritability
  • cramps

If your child seems extra tired or moody, he may just be a bit dehydrated. These can also be signs of low blood sugar (i.e. being “hangry”). So if these symptoms are popping up, assess if your child needs food or water or both!

If left untreated, dehydration can become more severe. Signs of worse dehydration include:

  • heartburn
  • back pain
  • migraines
  • constipation
  • colitis
  • joint pain
Kids playing in field

If your child is regularly dealing with constipation, heartburn, and headaches, it’s time to increase fluid intake. It is also important to talk to your doctor if your child is experiencing these mature signs of dehydration on a regular basis.

What Causes Dehydration in Kids?

Stated plainly, kids get dehydrated when they either don’t drink enough water to meet the demands of their bodies or if they are not absorbing the water they do drink.

Water can not be stored in the body, so it must be replenished on a daily basis. It is used by the GI tract, lungs, skin, and kidneys to function properly. The largest portion of water is used by the kidneys, about 60%. If a child is dehydrated, their urine output will decrease to preserve kidney function. Watch for a decrease in urination or darker urine as a symptom of dehydration.

Active kids sweat, releasing water via the skin. So if your kids are playing sports or just running around, they need to replace the lost fluids.

Ingested water is mostly absorbed in the small intestines. If your child has poor gut health, including gut dysbiosis (“leaky gut”), he may have a harder time absorbing fluids properly.

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Role of Kidneys in Hydration

The kidneys are essential organs when it comes to hydration. A few of the major roles of the kidneys include:

  • filter and remove waste from the blood
  • create urine
  • recycle water and solutes back into the bloodstream
  • regulate blood pressure (by adjusting blood flow into and out of kidneys)
  • regulate blood pH
  • regulate blood levels of sodium, potassium, calcium, chloride, and phosphate
  • regulate blood volume
Glasses of colored water

The last point is especially important. Kidneys regulate blood volume by conserving or eliminating water. If your child is dehydrated, the kidneys will conserve water to keep blood volume stable.

How to Prevent Dehydration in Kids

The flip side of conserving water is eliminating water. Certain beverages slow down the process of the kidneys reabsorbing water. So water that should be recycled back into the bloodstream is instead flushed out as urine, leading to dehydration in kids.

This is caused by substances referred to as diuretics. These can include:

  • pop/soda
  • juice
  • tea
  • coffee (caffeine)
  • some prescription medications

Diuretics should be avoided or kept to a minimum. The extra water lost from diuretics must also be replaced.

Many diuretics are also sources of sugar. Added sugar will weaken the immune system, impair blood sugar regulation, and deplete essential minerals. So it is best to avoid soft drinks, caffeinated beverages, and juice.

RELATED: 6 strategies to reduce your child’s sugar intake here!

Water bottle pouring

How Much Water Should Kids Drink?

A good rule of thumb is for kids to drink half their body weight in water.

Body weight in lbs./2 = daily ounces of water

If diuretics are consumed, consider adding extra minerals to the diet as diuretics can lead to overhydration.

That being said, letting your child listen to her body is the best way to stay hydrated. There is no need to force kids to drink water. Simply make it easily available at all times. If your child tends to forget to drink water or is often dehydrated, try reminding her to take sips throughout the day.

What are the Best Beverages for Hydration?

Hands down the best beverage for keeping kids hydrated is plain, filtered water!

But depending on the child, plain water may not be enough.

Another important factor in hydration is electrolytes. This includes trace minerals and unrefined sea salt. In order for the body to absorb water, it needs electrolytes.

Adding a pinch of salt or trace mineral drops to water can make all the difference. There are strawberry-flavored trace mineral drops that work well for kids. The water tastes like strawberries! This is a great solution for kids that don’t like drinking plain water.

Coconut water is another great option as it is a natural source of several minerals like potassium and sodium. Just be sure to get pure coconut water. Some varieties have sugar added.

A non-traditional way to hydrate is with special versions of hot cocoa (get the recipe here) or salted chocolate milk (get the recipe here). They are definitely favorites at our house!

Milk can be another good option as it naturally has minerals. Just be sure it is of high quality.

RELATED: Hydrating Watermelon Slushie Recipe (with NO ADDED SUGAR!) 

homemade smart water

Hydration for Athletes

The above suggestions are for everyday hydration. If your child is playing sports he may need a bit more to stay hydrated.

You can make a super simple homemade electrolyte drink with water, lemon juice, honey, and real salt or trace minerals.

This copycat Gatorade is another great option!

Or if you really want to pack a punch of nutrition while also hydrating, try this homemade “Smart” water. It’s like a multi-vitamin and hydration all in one.

Splash of water

Can Kids be Over-hydrated?

Although dehydration is more common, it is possible for kids to be over-hydrated. If your child drinks a lot of plain water (whether by choice or because they are encouraged to do so) they could become over-hydrated.

This can have it’s own health implications.

Over-hydration leads to too much water being excreted by the kidneys and loss of essential minerals. This disrupts the normal function of the kidneys and can lead to the same symptoms as dehydration.

Other signs to watch for are:

  • very pale or clear urine (urine should have some color to it – a lighter yellow – but not pale)
  • frequent urination
  • low body temperature/feeling cold often
  • fatigue

Simply reducing water intake may be the solution. But more likely adding essential electrolytes (trace minerals and unrefined salt) will be the solution.

Girl holding waterbottle

An Active Eater tends to be a water guzzler. So if you have an Active Eater, make sure you are adding electrolytes to her water, and teach her to sip water instead of drinking a whole glass at once. Not sure what type of eater you have? Find out HERE!

How to Keep Kids Hydrated

Keeping your kids hydrated doesn’t have to be complicated.

  1. Keep a water cup available at all times (on the table, on the counter, in a backpack, at a school desk, etc.).
  2. Add trace minerals and salt to water for better absorption.
  3. Provide other hydrating drinks during physical activity or if your child is already dehydrated or sick.
  4. Watch urine output and color for signs of dehydration or over-hydration.
  5. Watch for symptoms of dehydration to stop it early.
  6. Avoid diuretics and sugar.

The next time your child seems a little extra tired or complains of a headache, mix up a quick electrolyte drink. You’ll be amazed at what a difference proper hydration can make!

What is your favorite way to keep your kids hydrated?

Looking for more information on hydration and water? Check out these links.

Unless otherwise credited, photos are owned by the author or used with a license from Canva or Deposit Photos.

2 thoughts on “Signs of Dehydration in Children: How to Tell if Your Kids Are Dehydrated and What to Do About It!”


    Hi Katie, thank you for posting this info about the most important nutrient. I was already in College when I first learned about and implemented a regular water drinking schedule – rather late than never! That definately improved my health on so many levels. Getting my kiddo interested in drinking water though has been an interesting challenge. I came up with the idea of putting stickers on a clear drinking cup when she was around four and it has been a breakthrough! I’d ask her to pick a sticker and then I’d put it where the water line needed to stop. She liked that. In our home we have wake up water time, morning water time (1-2 hours after BF) and afternoon water time (1-2 hours after lunch) and some before bedtime if she wanted. She is six now so needs six cups a day. She drinks about two cups at each of the drinking times.

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